    /**
     * This class encapsulates the user interface for a tabular data set.
     * It acts as a centralized manager for controlling the various interface
     * elements of the view. This includes handling events, such as row and cell
     * level based DOM events. It also reacts to events from the underlying {@link Ext.selection.Model}
     * to provide visual feedback to the user.
     *
     * This class does not provide ways to manipulate the underlying data of the configured
     * {@link Ext.data.Store}.
     *
     * This is the base class for both {@link Ext.grid.View} and {@link Ext.tree.View} and is not
     * to be used directly.
     */
    Ext.define('Ext.view.Table', {
        extend: 'Ext.view.View',
        alias: 'widget.tableview',
        uses: [
            'Ext.view.TableChunker',
            'Ext.util.DelayedTask',
            'Ext.util.MixedCollection'
        ],

        baseCls: Ext.baseCSSPrefix + 'grid-view',

        // row
        itemSelector: 'tr.' + Ext.baseCSSPrefix + 'grid-row',
        // cell
        cellSelector: 'td.' + Ext.baseCSSPrefix + 'grid-cell',

        // keep a separate rowSelector, since we may need to select the actual row elements
        rowSelector: 'tr.' + Ext.baseCSSPrefix + 'grid-row',

        /**
         * @cfg {String} [firstCls='x-grid-cell-first']
         * A CSS class to add to the *first* cell in every row to enable special styling for the first column.
         * If no styling is needed on the first column, this may be configured as `null`.
         */
        firstCls: Ext.baseCSSPrefix + 'grid-cell-first',

        /**
         * @cfg {String} [lastCls='x-grid-cell-last']
         * A CSS class to add to the *last* cell in every row to enable special styling for the last column.
         * If no styling is needed on the last column, this may be configured as `null`.
         */
        lastCls: Ext.baseCSSPrefix + 'grid-cell-last',

        headerRowSelector: 'tr.' + Ext.baseCSSPrefix + 'grid-header-row',

        selectedItemCls: Ext.baseCSSPrefix + 'grid-row-selected',
        selectedCellCls: Ext.baseCSSPrefix + 'grid-cell-selected',
        focusedItemCls: Ext.baseCSSPrefix + 'grid-row-focused',
        overItemCls: Ext.baseCSSPrefix + 'grid-row-over',
        altRowCls:   Ext.baseCSSPrefix + 'grid-row-alt',
        rowClsRe: new RegExp('(?:^|\\s*)' + Ext.baseCSSPrefix + 'grid-row-(first|last|alt)(?:\\s+|$)', 'g'),
        cellRe: new RegExp(Ext.baseCSSPrefix + 'grid-cell-([^\\s]+) ', ''),

        // cfg docs inherited
        trackOver: true,

        /**
         * Override this function to apply custom CSS classes to rows during rendering. This function should return the
         * CSS class name (or empty string '' for none) that will be added to the row's wrapping div. To apply multiple
         * class names, simply return them space-delimited within the string (e.g. 'my-class another-class').
         * Example usage:
         *
         *     viewConfig: {
         *         getRowClass: function(record, rowIndex, rowParams, store){
         *             return record.get("valid") ? "row-valid" : "row-error";
         *         }
         *     }
         *
         * @param {Ext.data.Model} record The record corresponding to the current row.
         * @param {Number} index The row index.
         * @param {Object} rowParams **DEPRECATED.** For row body use the
         * {@link Ext.grid.feature.RowBody#getAdditionalData getAdditionalData} method of the rowbody feature.
         * @param {Ext.data.Store} store The store this grid is bound to
         * @return {String} a CSS class name to add to the row.
         * @method
         */
        getRowClass: null,

        /**
         * @cfg {Boolean} stripeRows
         * True to stripe the rows.
         *
         * This causes the CSS class **`x-grid-row-alt`** to be added to alternate rows of
         * the grid. A default CSS rule is provided which sets a background color, but you can override this
         * with a rule which either overrides the **background-color** style using the `!important`
         * modifier, or which uses a CSS selector of higher specificity.
         */
        stripeRows: true,

        /**
         * @cfg {Boolean} markDirty
         * True to show the dirty cell indicator when a cell has been modified.
         */
        markDirty : true,

        /**
         * @cfg {Boolean} enableTextSelection
         * True to enable text selections.
         */

        initComponent: function() {
            var me = this,
                scroll = me.scroll;

            // Scrolling within a TableView is controlled by the scroll config of its owning GridPanel
            // It must see undefined in this property in order to leave the scroll styles alone at afterRender time
            me.autoScroll = undefined;

            //Scrolling is handled at the View's element level
            if (scroll === true || scroll === 'both') {
                me.style = Ext.apply(me.style||{}, {
                    overflow: 'auto'
                });
            } else if (scroll === 'horizontal') {
                me.style = Ext.apply(me.style||{}, {
                    "overflow-x": 'auto',
                    "overflow-y": 'hidden'
                });
            } else if (scroll === 'vertical') {
                me.style = Ext.apply(me.style||{}, {
                    "overflow-x": 'hidden',
                    "overflow-y": 'auto'
                });
            } else {
                me.style = Ext.apply(me.style||{}, {
                    overflow: 'hidden'
                });
            }
            me.selModel.view = me;
            me.headerCt.view = me;
            me.headerCt.markDirty = me.markDirty;

            // Features need a reference to the grid.
            me.initFeatures(me.grid);
            delete me.grid;

            me.tpl = '<div></div>';
            me.callParent();
        },

        /**
         * @private
         * Move a grid column from one position to another
         * @param {Number} fromIdx The index from which to move columns
         * @param {Number} toIdx The index at which to insert columns.
         * @param {Number} [colsToMove=1] The number of columns to move beginning at the `fromIdx`
         */
        moveColumn: function(fromIdx, toIdx, colsToMove) {
            var me = this,
                fragment = (colsToMove > 1) ? document.createDocumentFragment() : undefined,
                destinationCellIdx = toIdx,
                colCount = me.getGridColumns().length,
                lastIdx = colCount - 1,
                doFirstLastClasses = (me.firstCls || me.lastCls) && (toIdx == 0 || toIdx == colCount || fromIdx == 0 || fromIdx == lastIdx),
                i,
                j,
                rows, len, tr, headerRows;

            if (me.rendered) {
                // Use select here. In most cases there will only be one row. In
                // the case of a grouping grid, each group also has a header.
                headerRows = me.el.query(me.headerRowSelector);
                rows = me.el.query(me.rowSelector);

                if (toIdx > fromIdx && fragment) {
                    destinationCellIdx -= colsToMove;
                }

                // Move the column sizing header to match
                for (i = 0, len = headerRows.length; i < len; ++i) {
                    tr = headerRows[i];
                    if (fragment) {
                        for (j = 0; j < colsToMove; j++) {
                            fragment.appendChild(tr.cells[fromIdx]);
                        }
                        tr.insertBefore(fragment, tr.cells[destinationCellIdx] || null);
                    } else {
                        tr.insertBefore(tr.cells[fromIdx], tr.cells[destinationCellIdx] || null);
                    }
                }

                for (i = 0, len = rows.length; i < len; i++) {
                    tr = rows[i];

                    // Keep first cell class and last cell class correct *only if needed*
                    if (doFirstLastClasses) {

                        if (fromIdx === 0) {
                            Ext.fly(tr.cells[0]).removeCls(me.firstCls);
                            Ext.fly(tr.cells[1]).addCls(me.firstCls);
                        } else if (fromIdx === lastIdx) {
                            Ext.fly(tr.cells[lastIdx]).removeCls(me.lastCls);
                            Ext.fly(tr.cells[lastIdx - 1]).addCls(me.lastCls);
                        }
                        if (toIdx === 0) {
                            Ext.fly(tr.cells[0]).removeCls(me.firstCls);
                            Ext.fly(tr.cells[fromIdx]).addCls(me.firstCls);
                        } else if (toIdx === colCount) {
                            Ext.fly(tr.cells[lastIdx]).removeCls(me.lastCls);
                            Ext.fly(tr.cells[fromIdx]).addCls(me.lastCls);
                        }
                    }

                    if (fragment) {
                        for (j = 0; j < colsToMove; j++) {
                            fragment.appendChild(tr.cells[fromIdx]);
                        }
                        tr.insertBefore(fragment, tr.cells[destinationCellIdx] || null);
                    } else {
                        tr.insertBefore(tr.cells[fromIdx], tr.cells[destinationCellIdx] || null);
                    }
                }
                me.setNewTemplate();
            }
        },

        // scroll the view to the top
        scrollToTop: Ext.emptyFn,

        /**
         * Add a listener to the main view element. It will be destroyed with the view.
         * @private
         */
        addElListener: function(eventName, fn, scope){
            this.mon(this, eventName, fn, scope, {
                element: 'el'
            });
        },

        /**
         * Get the columns used for generating a template via TableChunker.
         * See {@link Ext.grid.header.Container#getGridColumns}.
         * @private
         */
        getGridColumns: function() {
            return this.headerCt.getGridColumns();
        },

        /**
         * Get a leaf level header by index regardless of what the nesting
         * structure is.
         * @private
         * @param {Number} index The index
         */
        getHeaderAtIndex: function(index) {
            return this.headerCt.getHeaderAtIndex(index);
        },

        /**
         * Get the cell (td) for a particular record and column.
         * @param {Ext.data.Model} record
         * @param {Ext.grid.column.Column} column
         * @private
         */
        getCell: function(record, column) {
            var row = this.getNode(record);
            return Ext.fly(row).down(column.getCellSelector());
        },

        /**
         * Get a reference to a feature
         * @param {String} id The id of the feature
         * @return {Ext.grid.feature.Feature} The feature. Undefined if not found
         */
        getFeature: function(id) {
            var features = this.featuresMC;
            if (features) {
                return features.get(id);
            }
        },

        /**
         * Initializes each feature and bind it to this view.
         * @private
         */
        initFeatures: function(grid) {
            var me = this,
                i,
                features,
                feature,
                len;

            me.featuresMC = new Ext.util.MixedCollection();
            features = me.features = me.prepareFeatures();
            len = features ? features.length : 0;
            for (i = 0; i < len; i++) {
                feature = features[i];

                // inject a reference to view and grid - Features need both
                feature.view = me;
                feature.grid = grid;
                me.featuresMC.add(feature);
                feature.init();
            }
        },

        /**
         * @private
         * Converts the features array as configured, into an array of instantiated Feature objects.
         *
         * This is borrowed by Lockable which clones and distributes Features to both child grids of a locking grid.
         *
         * Must have no side effects other than Feature instantiation.
         *
         * MUST NOT update the this.features property, and MUST NOT update the instantiated Features.
         */
        prepareFeatures: function() {
            var me = this,
                features = me.features,
                feature,
                result,
                i = 0, len;

            if (features) {
                result = [];
                len = features.length;
                for (; i < len; i++) {
                    feature = features[i];
                    if (!feature.isFeature) {
                        feature = Ext.create('feature.' + feature.ftype, feature);
                    }
                    result[i] = feature;
                }
            }
            return result;
        },

        /**
         * Gives features an injection point to attach events to the markup that
         * has been created for this view.
         * @private
         */
        attachEventsForFeatures: function() {
            var features = this.features,
                ln       = features.length,
                i        = 0;

            for (; i < ln; i++) {
                if (features[i].isFeature) {
                    features[i].attachEvents();
                }
            }
        },

        afterRender: function() {
            var me = this;
            me.callParent();

            if (!me.enableTextSelection) {
                me.el.unselectable();
            }
            me.attachEventsForFeatures();
        },

        // Private template method implemented starting at the AbstractView class.
        onViewScroll: function(e, t) {
            this.callParent(arguments);
            this.fireEvent('bodyscroll', e, t);
        },

        /**
         * Uses the headerCt (Which is the repository of all information relating to Column definitions)
         * to transform data from dataIndex keys in a record to headerId keys in each header and then run
         * them through each feature to get additional data for variables they have injected into the view template.
         * @private
         */
        prepareData: function(data, idx, record) {
            var me       = this,
                result   = me.headerCt.prepareData(data, idx, record, me, me.ownerCt),
                features = me.features,
                ln       = features.length,
                i        = 0,
                feature;

            for (; i < ln; i++) {
                feature = features[i];
                if (feature.isFeature) {
                    Ext.apply(result, feature.getAdditionalData(data, idx, record, result, me));
                }
            }

            return result;
        },

        // TODO: Refactor headerCt dependency here to colModel
        collectData: function(records, startIndex) {
            var preppedRecords = this.callParent(arguments),
                headerCt  = this.headerCt,
                fullWidth = headerCt.getFullWidth(),
                features  = this.features,
                ln = features.length,
                o = {
                    rows: preppedRecords,
                    fullWidth: fullWidth
                },
                i  = 0,
                feature,
                j = 0,
                jln,
                rowParams,
                rec,
                cls;

            jln = preppedRecords.length;
            // process row classes, rowParams has been deprecated and has been moved
            // to the individual features that implement the behavior.
            if (this.getRowClass) {
                for (; j < jln; j++) {
                    rowParams = {};
                    rec = preppedRecords[j];
                    cls = rec.rowCls || '';
                    rec.rowCls = this.getRowClass(records[j], j, rowParams, this.store) + ' ' + cls;
                    //<debug>
                    if (rowParams.alt) {
                        Ext.Error.raise("The getRowClass alt property is no longer supported.");
                    }
                    if (rowParams.tstyle) {
                        Ext.Error.raise("The getRowClass tstyle property is no longer supported.");
                    }
                    if (rowParams.cells) {
                        Ext.Error.raise("The getRowClass cells property is no longer supported.");
                    }
                    if (rowParams.body) {
                        Ext.Error.raise("The getRowClass body property is no longer supported. Use the getAdditionalData method of the rowbody feature.");
                    }
                    if (rowParams.bodyStyle) {
                        Ext.Error.raise("The getRowClass bodyStyle property is no longer supported.");
                    }
                    if (rowParams.cols) {
                        Ext.Error.raise("The getRowClass cols property is no longer supported.");
                    }
                    //</debug>
                }
            }
            // currently only one feature may implement collectData. This is to modify
            // what's returned to the view before its rendered
            for (; i < ln; i++) {
                feature = features[i];
                if (feature.isFeature && feature.collectData && !feature.disabled) {
                    o = feature.collectData(records, preppedRecords, startIndex, fullWidth, o);
                    break;
                }
            }
            return o;
        },

        /**
         * In FF10, flex columns transitioning from hidden to visible may not always be
         * displayed properly initially.  Simply re-measuring the width after the styling
         * changes take place seems to be enough to poke the browser into doing it's thing
         * @private
         */
        forceReflow: Ext.isGecko10
            ? function() {
                var el = this.el.down('table'),
                    width;
                if (el) {
                    width = el.getWidth();
                }
            }
            : Ext.emptyFn,

        /**
         * When a header is resized, setWidth on the individual columns resizer class,
         * the top level table, save/restore scroll state, generate a new template and
         * restore focus to the grid view's element so that keyboard navigation
         * continues to work.
         * @private
         */
        onHeaderResize: function(header, w, suppressFocus) {
            var me = this,
                el = me.el;

            if (el) {
                // Grab the col and set the width, css
                // class is generated in TableChunker.
                // Select composites because there may be several chunks.
                el.select('th.' + Ext.baseCSSPrefix + 'grid-col-resizer-'+header.id).setWidth(w);
                el.select('table.' + Ext.baseCSSPrefix + 'grid-table-resizer').setWidth(me.headerCt.getFullWidth());
                if (!me.ignoreTemplate) {
                    me.setNewTemplate();
                }
                if (!suppressFocus) {
                    me.el.focus();
                }
                me.forceReflow();
            }
        },

        /**
         * When a header is shown restore its oldWidth if it was previously hidden.
         * @private
         */
        onHeaderShow: function(headerCt, header, suppressFocus) {
            var me = this;
            me.ignoreTemplate = true;
            // restore headers that were dynamically hidden
            if (header.oldWidth) {
                me.onHeaderResize(header, header.oldWidth, suppressFocus);
                delete header.oldWidth;
            // flexed headers will have a calculated size set
            // this additional check has to do with the fact that
            // defaults: {width: 100} will fight with a flex value
            } else if (header.width && !header.flex) {
                me.onHeaderResize(header, header.width, suppressFocus);
            } else if (header.el) {
                me.onHeaderResize(header, header.el.getWidth(), suppressFocus);
            }
            delete me.ignoreTemplate;
            me.setNewTemplate();
        },

        /**
         * When the header hides treat it as a resize to 0.
         * @private
         */
        onHeaderHide: function(headerCt, header, suppressFocus) {
            this.onHeaderResize(header, 0, suppressFocus);
        },

        // Private. Called when the table changes height.
        // For example, see examples/grid/group-summary-grid.html
        // If we have flexed column headers, we need to update the header layout
        // because it may have to accommodate (or cease to accommodate) a vertical scrollbar.
        // Only do this on platforms with have a space-consuming scrollbar
        refreshSize: function() {
            var me = this,
                cmp;

            if (!me.hasLoadingHeight) {
                cmp = me.up('tablepanel');

                // Suspend layouts in case the superclass requests a layout. We might too, so they
                // must be coalescsed.
                Ext.suspendLayouts();

                me.callParent();

                if (cmp && Ext.getScrollbarSize().width) {
                    cmp.updateLayout();
                }

                Ext.resumeLayouts(true);
            }
        },

        /**
         * Set a new template based on the current columns displayed in the grid.
         * @private
         */
        setNewTemplate: function() {
            var me = this,
                columns = me.headerCt.getColumnsForTpl(true);

            // Template generation requires the rowCount as well as the column definitions and features.
            me.tpl = me.getTableChunker().getTableTpl({
                rowCount: me.store.getCount(),
                columns: columns,
                features: me.features,
                enableTextSelection: me.enableTextSelection
            });
        },

        /**
         * Returns the configured chunker or default of Ext.view.TableChunker
         */
        getTableChunker: function() {
            return this.chunker || Ext.view.TableChunker;
        },

        /**
         * Adds a CSS Class to a specific row.
         * @param {HTMLElement/String/Number/Ext.data.Model} rowInfo An HTMLElement, index or instance of a model
         * representing this row
         * @param {String} cls
         */
        addRowCls: function(rowInfo, cls) {
            var row = this.getNode(rowInfo);
            if (row) {
                Ext.fly(row).addCls(cls);
            }
        },

        /**
         * Removes a CSS Class from a specific row.
         * @param {HTMLElement/String/Number/Ext.data.Model} rowInfo An HTMLElement, index or instance of a model
         * representing this row
         * @param {String} cls
         */
        removeRowCls: function(rowInfo, cls) {
            var row = this.getNode(rowInfo);
            if (row) {
                Ext.fly(row).removeCls(cls);
            }
        },

        // GridSelectionModel invokes onRowSelect as selection changes
        onRowSelect : function(rowIdx) {
            this.addRowCls(rowIdx, this.selectedItemCls);
        },

        // GridSelectionModel invokes onRowDeselect as selection changes
        onRowDeselect : function(rowIdx) {
            var me = this;

            me.removeRowCls(rowIdx, me.selectedItemCls);
            me.removeRowCls(rowIdx, me.focusedItemCls);
        },

        onCellSelect: function(position) {
            var cell = this.getCellByPosition(position);
            if (cell) {
                cell.addCls(this.selectedCellCls);
            }
        },

        onCellDeselect: function(position) {
            var cell = this.getCellByPosition(position);
            if (cell) {
                cell.removeCls(this.selectedCellCls);
            }

        },

        onCellFocus: function(position) {
            this.focusCell(position);
        },

        getCellByPosition: function(position) {
            if (position) {
                var node   = this.getNode(position.row),
                    header = this.headerCt.getHeaderAtIndex(position.column);

                if (header && node) {
                    return Ext.fly(node).down(header.getCellSelector());
                }
            }
            return false;
        },

        // GridSelectionModel invokes onRowFocus to 'highlight'
        // the last row focused
        onRowFocus: function(rowIdx, highlight, supressFocus) {
            var me = this;

            if (highlight) {
                me.addRowCls(rowIdx, me.focusedItemCls);
                if (!supressFocus) {
                    me.focusRow(rowIdx);
                }
                //this.el.dom.setAttribute('aria-activedescendant', row.id);
            } else {
                me.removeRowCls(rowIdx, me.focusedItemCls);
            }
        },

        /**
         * Focuses a particular row and brings it into view. Will fire the rowfocus event.
         * @param {HTMLElement/String/Number/Ext.data.Model} rowIdx
         * An HTMLElement template node, index of a template node, the id of a template node or the
         * record associated with the node.
         */
        focusRow: function(rowIdx) {
            var me         = this,
                row        = me.getNode(rowIdx),
                el         = me.el,
                adjustment = 0,
                panel      = me.ownerCt,
                rowRegion,
                elTop,
                elBottom,
                record;

            if (row && el) {
                // Viewable region must not include scrollbars, so use
                // DOM clientHeight to determine height
                elTop = el.getY();
                elBottom = elTop + el.dom.clientHeight;
                rowRegion = Ext.fly(row).getRegion();
                // row is above
                if (rowRegion.top < elTop) {
                    adjustment = rowRegion.top - elTop;
                // row is below
                } else if (rowRegion.bottom > elBottom) {
                    adjustment = rowRegion.bottom - elBottom;
                }
                record = me.getRecord(row);
                rowIdx = me.store.indexOf(record);

                if (adjustment) {
                    panel.scrollByDeltaY(adjustment);
                }
                me.fireEvent('rowfocus', record, row, rowIdx);
            }
        },

        focusCell: function(position) {
            var me          = this,
                cell        = me.getCellByPosition(position),
                el          = me.el,
                adjustmentY = 0,
                adjustmentX = 0,
                elRegion    = el.getRegion(),
                panel       = me.ownerCt,
                cellRegion,
                record;

            // Viewable region must not include scrollbars, so use
            // DOM client dimensions
            elRegion.bottom = elRegion.top + el.dom.clientHeight;
            elRegion.right = elRegion.left + el.dom.clientWidth;
            if (cell) {
                cellRegion = cell.getRegion();
                // cell is above
                if (cellRegion.top < elRegion.top) {
                    adjustmentY = cellRegion.top - elRegion.top;
                // cell is below
                } else if (cellRegion.bottom > elRegion.bottom) {
                    adjustmentY = cellRegion.bottom - elRegion.bottom;
                }

                // cell is left
                if (cellRegion.left < elRegion.left) {
                    adjustmentX = cellRegion.left - elRegion.left;
                // cell is right
                } else if (cellRegion.right > elRegion.right) {
                    adjustmentX = cellRegion.right - elRegion.right;
                }

                if (adjustmentY) {
                    panel.scrollByDeltaY(adjustmentY);
                }
                if (adjustmentX) {
                    panel.scrollByDeltaX(adjustmentX);
                }
                el.focus();
                me.fireEvent('cellfocus', record, cell, position);
            }
        },

        /**
         * Scrolls by delta. This affects this individual view ONLY and does not
         * synchronize across views or scrollers.
         * @param {Number} delta
         * @param {String} [dir] Valid values are scrollTop and scrollLeft. Defaults to scrollTop.
         * @private
         */
        scrollByDelta: function(delta, dir) {
            dir = dir || 'scrollTop';
            var elDom = this.el.dom;
            elDom[dir] = (elDom[dir] += delta);
        },

        // private
        onUpdate : function(store, record, operation, changedFieldNames) {
            var me = this,
                index,
                newRow, oldRow,
                oldCells, newCells, len, i,
                columns, overItemCls,
                isHovered, row;

            if (me.rendered) {

                index = me.store.indexOf(record);
                columns = me.headerCt.getGridColumns();
                overItemCls = me.overItemCls;

                // If we have columns which may *need* updating (think lockable grid child with all columns either locked or unlocked)
                // and the changed record is within our view, then update the view
                if (columns.length && index > -1) {
                    newRow = me.bufferRender([record], index)[0];
                    oldRow = me.all.item(index);
                    isHovered = oldRow.hasCls(overItemCls);
                    oldRow.dom.className = newRow.className;
                    if(isHovered) {
                        oldRow.addCls(overItemCls);
                    }

                    // Replace changed cells in the existing row structure with the new version from the rendered row.
                    oldCells = oldRow.query(this.cellSelector);
                    newCells = Ext.fly(newRow).query(this.cellSelector);
                    len = newCells.length;
                    // row is the element that contains the cells.  This will be a different element from oldRow when using a rowwrap feature
                    row = oldCells[0].parentNode;
                    for (i = 0; i < len; i++) {
                        // If the field at this column index was changed, replace the cell.
                        if (me.shouldUpdateCell(columns[i], changedFieldNames)) {
                            row.insertBefore(newCells[i], oldCells[i]);
                            row.removeChild(oldCells[i]);
                        }
                    }

                    // Maintain selection after update
                    // TODO: Move to approriate event handler.
                    me.selModel.refresh();
                    me.doStripeRows(index, index);
                    me.fireEvent('itemupdate', record, index, newRow);
                }
            }

        },

        shouldUpdateCell: function(column, changedFieldNames){
            // Though this may not be the most efficient, a renderer could be dependent on any field in the
            // store, so we must always update the cell
            if (column.hasCustomRenderer) {
                return true;
            }
            return !changedFieldNames || Ext.Array.contains(changedFieldNames, column.dataIndex);
        },

        /**
         * Refreshes the grid view. Saves and restores the scroll state, generates a new template, stripes rows and
         * invalidates the scrollers.
         */
        refresh: function() {
            this.setNewTemplate();
            this.callParent(arguments);
            this.doStripeRows(0);
        },

        processItemEvent: function(record, row, rowIndex, e) {
            var me = this,
                cell = e.getTarget(me.cellSelector, row),
                cellIndex = cell ? cell.cellIndex : -1,
                map = me.statics().EventMap,
                selModel = me.getSelectionModel(),
                type = e.type,
                result;

            if (type == 'keydown' && !cell && selModel.getCurrentPosition) {
                // CellModel, otherwise we can't tell which cell to invoke
                cell = me.getCellByPosition(selModel.getCurrentPosition());
                if (cell) {
                    cell = cell.dom;
                    cellIndex = cell.cellIndex;
                }
            }

            result = me.fireEvent('uievent', type, me, cell, rowIndex, cellIndex, e, record, row);

            if (result === false || me.callParent(arguments) === false) {
                return false;
            }

            // Don't handle cellmouseenter and cellmouseleave events for now
            if (type == 'mouseover' || type == 'mouseout') {
                return true;
            }

            if(!cell) {
                // if the element whose event is being processed is not an actual cell (for example if using a rowbody
                // feature and the rowbody element's event is being processed) then do not fire any "cell" events
                return true;
            }

            return !(
                // We are adding cell and feature events
                (me['onBeforeCell' + map[type]](cell, cellIndex, record, row, rowIndex, e) === false) ||
                (me.fireEvent('beforecell' + type, me, cell, cellIndex, record, row, rowIndex, e) === false) ||
                (me['onCell' + map[type]](cell, cellIndex, record, row, rowIndex, e) === false) ||
                (me.fireEvent('cell' + type, me, cell, cellIndex, record, row, rowIndex, e) === false)
            );
        },

        processSpecialEvent: function(e) {
            var me = this,
                map = me.statics().EventMap,
                features = me.features,
                ln = features.length,
                type = e.type,
                i, feature, prefix, featureTarget,
                beforeArgs, args,
                panel = me.ownerCt;

            me.callParent(arguments);

            if (type == 'mouseover' || type == 'mouseout') {
                return;
            }

            for (i = 0; i < ln; i++) {
                feature = features[i];
                if (feature.hasFeatureEvent) {
                    featureTarget = e.getTarget(feature.eventSelector, me.getTargetEl());
                    if (featureTarget) {
                        prefix = feature.eventPrefix;
                        // allows features to implement getFireEventArgs to change the
                        // fireEvent signature
                        beforeArgs = feature.getFireEventArgs('before' + prefix + type, me, featureTarget, e);
                        args = feature.getFireEventArgs(prefix + type, me, featureTarget, e);

                        if (
                            // before view event
                            (me.fireEvent.apply(me, beforeArgs) === false) ||
                            // panel grid event
                            (panel.fireEvent.apply(panel, beforeArgs) === false) ||
                            // view event
                            (me.fireEvent.apply(me, args) === false) ||
                            // panel event
                            (panel.fireEvent.apply(panel, args) === false)
                        ) {
                            return false;
                        }
                    }
                }
            }
            return true;
        },

        onCellMouseDown: Ext.emptyFn,
        onCellMouseUp: Ext.emptyFn,
        onCellClick: Ext.emptyFn,
        onCellDblClick: Ext.emptyFn,
        onCellContextMenu: Ext.emptyFn,
        onCellKeyDown: Ext.emptyFn,
        onBeforeCellMouseDown: Ext.emptyFn,
        onBeforeCellMouseUp: Ext.emptyFn,
        onBeforeCellClick: Ext.emptyFn,
        onBeforeCellDblClick: Ext.emptyFn,
        onBeforeCellContextMenu: Ext.emptyFn,
        onBeforeCellKeyDown: Ext.emptyFn,

        /**
         * Expands a particular header to fit the max content width.
         * This will ONLY expand, not contract.
         * @private
         */
        expandToFit: function(header) {
            if (header) {
                var maxWidth = this.getMaxContentWidth(header);
                delete header.flex;
                header.setWidth(maxWidth);
            }
        },

        /**
         * Returns the max contentWidth of the header's text and all cells
         * in the grid under this header.
         * @private
         */
        getMaxContentWidth: function(header) {
            var cellSelector = header.getCellInnerSelector(),
                cells        = this.el.query(cellSelector),
                i = 0,
                ln = cells.length,
                maxWidth = header.el.dom.scrollWidth,
                scrollWidth;

            for (; i < ln; i++) {
                scrollWidth = cells[i].scrollWidth;
                if (scrollWidth > maxWidth) {
                    maxWidth = scrollWidth;
                }
            }
            return maxWidth;
        },

        getPositionByEvent: function(e) {
            var me       = this,
                cellNode = e.getTarget(me.cellSelector),
                rowNode  = e.getTarget(me.itemSelector),
                record   = me.getRecord(rowNode),
                header   = me.getHeaderByCell(cellNode);

            return me.getPosition(record, header);
        },

        getHeaderByCell: function(cell) {
            if (cell) {
                var m = cell.className.match(this.cellRe);
                if (m && m[1]) {
                    return Ext.getCmp(m[1]);
                }
            }
            return false;
        },

        /**
         * @param {Object} position The current row and column: an object containing the following properties:
         *
         * - row - The row index
         * - column - The column index
         *
         * @param {String} direction 'up', 'down', 'right' and 'left'
         * @param {Ext.EventObject} e event
         * @param {Boolean} preventWrap Set to true to prevent wrap around to the next or previous row.
         * @param {Function} verifierFn A function to verify the validity of the calculated position.
         * When using this function, you must return true to allow the newPosition to be returned.
         * @param {Object} scope Scope to run the verifierFn in
         * @returns {Object} newPosition An object containing the following properties:
         *
         * - row - The row index
         * - column - The column index
         *
         * @private
         */
        walkCells: function(pos, direction, e, preventWrap, verifierFn, scope) {

            // Caller (probably CellModel) had no current position. This can happen
            // if the main el is focused and any navigation key is presssed.
            if (!pos) {
                return;
            }

            var me       = this,
                row      = pos.row,
                column   = pos.column,
                rowCount = me.store.getCount(),
                firstCol = me.getFirstVisibleColumnIndex(),
                lastCol  = me.getLastVisibleColumnIndex(),
                newPos   = {row: row, column: column},
                activeHeader = me.headerCt.getHeaderAtIndex(column);

            // no active header or its currently hidden
            if (!activeHeader || activeHeader.hidden) {
                return false;
            }

            e = e || {};
            direction = direction.toLowerCase();
            switch (direction) {
                case 'right':
                    // has the potential to wrap if its last
                    if (column === lastCol) {
                        // if bottom row and last column, deny right
                        if (preventWrap || row === rowCount - 1) {
                            return false;
                        }
                        if (!e.ctrlKey) {
                            // otherwise wrap to nextRow and firstCol
                            newPos.row = row + 1;
                            newPos.column = firstCol;
                        }
                    // go right
                    } else {
                        if (!e.ctrlKey) {
                            newPos.column = column + me.getRightGap(activeHeader);
                        } else {
                            newPos.column = lastCol;
                        }
                    }
                    break;

                case 'left':
                    // has the potential to wrap
                    if (column === firstCol) {
                        // if top row and first column, deny left
                        if (preventWrap || row === 0) {
                            return false;
                        }
                        if (!e.ctrlKey) {
                            // otherwise wrap to prevRow and lastCol
                            newPos.row = row - 1;
                            newPos.column = lastCol;
                        }
                    // go left
                    } else {
                        if (!e.ctrlKey) {
                            newPos.column = column + me.getLeftGap(activeHeader);
                        } else {
                            newPos.column = firstCol;
                        }
                    }
                    break;

                case 'up':
                    // if top row, deny up
                    if (row === 0) {
                        return false;
                    // go up
                    } else {
                        if (!e.ctrlKey) {
                            newPos.row = row - 1;
                        } else {
                            newPos.row = 0;
                        }
                    }
                    break;

                case 'down':
                    // if bottom row, deny down
                    if (row === rowCount - 1) {
                        return false;
                    // go down
                    } else {
                        if (!e.ctrlKey) {
                            newPos.row = row + 1;
                        } else {
                            newPos.row = rowCount - 1;
                        }
                    }
                    break;
            }

            if (verifierFn && verifierFn.call(scope || window, newPos) !== true) {
                return false;
            } else {
                return newPos;
            }
        },
        getFirstVisibleColumnIndex: function() {
            var firstVisibleHeader = this.getHeaderCt().getVisibleGridColumns()[0];

            return firstVisibleHeader ? firstVisibleHeader.getIndex() : -1;
        },

        getLastVisibleColumnIndex: function() {
            var visHeaders = this.getHeaderCt().getVisibleGridColumns(),
                lastHeader = visHeaders[visHeaders.length - 1];

            return lastHeader.getIndex();
        },

        getHeaderCt: function() {
            return this.headerCt;
        },

        // TODO: have this use the new Ext.grid.CellContext class
        getPosition: function(record, header) {
            var me = this,
                store = me.store,
                gridCols = me.headerCt.getGridColumns();

            return {
                row: store.indexOf(record),
                column: Ext.Array.indexOf(gridCols, header)
            };
        },

        /**
         * Determines the 'gap' between the closest adjacent header to the right
         * that is not hidden.
         * @private
         */
        getRightGap: function(activeHeader) {
            var headerCt        = this.getHeaderCt(),
                headers         = headerCt.getGridColumns(),
                activeHeaderIdx = Ext.Array.indexOf(headers, activeHeader),
                i               = activeHeaderIdx + 1,
                nextIdx;

            for (; i <= headers.length; i++) {
                if (!headers[i].hidden) {
                    nextIdx = i;
                    break;
                }
            }

            return nextIdx - activeHeaderIdx;
        },

        beforeDestroy: function() {
            if (this.rendered) {
                this.el.removeAllListeners();
            }
            this.callParent(arguments);
        },

        /**
         * Determines the 'gap' between the closest adjacent header to the left
         * that is not hidden.
         * @private
         */
        getLeftGap: function(activeHeader) {
            var headerCt        = this.getHeaderCt(),
                headers         = headerCt.getGridColumns(),
                activeHeaderIdx = Ext.Array.indexOf(headers, activeHeader),
                i               = activeHeaderIdx - 1,
                prevIdx;

            for (; i >= 0; i--) {
                if (!headers[i].hidden) {
                    prevIdx = i;
                    break;
                }
            }

            return prevIdx - activeHeaderIdx;
        },

        // after adding a row stripe rows from then on
        onAdd: function(ds, records, index) {
            this.callParent(arguments);
            this.doStripeRows(index);
        },

        // after removing a row stripe rows from then on
        onRemove: function(ds, records, index) {
            this.callParent(arguments);
            this.doStripeRows(index);
        },

        /**
         * Stripes rows from a particular row index.
         * @param {Number} startRow
         * @param {Number} [endRow] argument specifying the last row to process.
         * By default process up to the last row.
         * @private
         */
        doStripeRows: function(startRow, endRow) {
            var me = this,
                rows,
                rowsLn,
                i,
                row;

            // ensure stripeRows configuration is turned on
            if (me.rendered && me.stripeRows) {
                rows = me.getNodes(startRow, endRow);

                for (i = 0, rowsLn = rows.length; i < rowsLn; i++) {
                    row = rows[i];
                    // Remove prior applied row classes.
                    row.className = row.className.replace(me.rowClsRe, ' ');
                    startRow++;
                    // Every odd row will get an additional cls
                    if (startRow % 2 === 0) {
                        row.className += (' ' + me.altRowCls);
                    }
                }
            }
        }

    });